And now to a new technology that could help alleviate another problem for automobiles: gridlock.

Carmakers are working to come up with some high-tech solutions to traffic jams.

As NPR's Annie Baxter reports, computerized cars could help reduce congestion on the roads.

ANNIE BAXTER, BYLINE: Just how chaotic will traffic be once four billion vehicles are clogging the world's roads by mid-century?

(SOUNDBITE OF TRAFFIC, HORN HONKING)

BAXTER: The executive chairman of Ford Motor Company doesn't want to know the answer.

BILL FORD, JR.: To me, that's a very unappealing prospect.

BAXTER: Bill Ford, Jr. delivered the keynote address at a big technology summit in Barcelona yesterday. And he talked about the need for automakers to take on the causes of global gridlock and traffic accidents. He said the stakes for doing so are high. People lose time and money sitting in traffic, and worse.

BAXTER: One of Ford's solutions involves getting cars to talk to each other and drive more closely together. That would alleviate congestion.

Bryant Walker Smith is an expert on Internet and automotive research at Stanford University. He says just about every automaker is looking into the kind of vehicle automation that could reduce traffic and accidents. Even Google's a player on this front with its concept for driverless cars. But Smith says some of these fancy new automation systems could have unintended consequences.

BRYANT WALKER SMITH: For example, a driver may feel more confident in checking the cell phone or even checking an email, believing that the system will catch their errors or alert them to issues.